A testing device for monitoring deformation and stress change of roadway surrounding rock

Abstract

This invention discloses a test device for monitoring deformation and stress changes in roadway surrounding rock, comprising: a mounting plate with four L-shaped vertical plates; a pressure assembly including multiple vertically mounted, rectangularly arranged pressing components on the mounting plate, each pressing component having a downward-facing telescopic end and a pressure plate at each telescopic end, the pressing components driving the pressure plate downward to apply test pressure to the test specimen; a detection assembly with a moving trolley at its bottom, the moving trolley driving the detection assembly to move closer to or further away from the test specimen, the detection assembly being able to insert into the corresponding test position on the test specimen during movement, and also being able to rotate, expand, or retract to cooperate with the pressing components in performing test measurements on the test specimen; and a sensing assembly mounted on the mounting plate. This invention can simulate relevant roadway conditions and perform test monitoring, thus facilitating practical use.

Description

Technical Field

[0001] This invention relates to the field of simulated tunnel testing technology, and in particular to a testing device for monitoring deformation and stress changes in the surrounding rock of a tunnel. Background Technology

[0002] With the continuous rise in domestic energy demand and the gradual depletion of shallow mineral resources, deep mining has become an inevitable trend in mineral resource development. The increasing depth and intensity of mining have led to increasingly complex underground geological conditions, significantly increased in-situ stress, developed rock fissures, and a substantial decrease in surrounding rock stability. This results in frequent deformation and instability of the surrounding rock in tunnels, severely restricting the safety and efficiency of deep mining. Similar material simulation experiments, based on the three similarity theorems, offer advantages such as good economy, strong controllability, and excellent visualization. They are a core experimental method for exploring the deformation laws and mechanical mechanisms of surrounding rock in underground engineering, and also an important supplement to field tests and numerical simulations.

[0003] The current simulation test system for surrounding rock in deep roadways still has significant shortcomings. The supporting technologies and equipment for monitoring surrounding rock are not yet perfect, and there is a lack of precise and dynamic methods for simultaneous monitoring of stress and displacement. Existing test methods obtain limited and inaccurate data on the mechanical properties of surrounding rock, making it difficult to fully capture the dynamic response of the entire process of deformation and instability in deep roadways. Furthermore, it is difficult to accurately reveal the mechanical mechanisms and evolution laws of surrounding rock instability, seriously affecting the theoretical research on surrounding rock control in deep roadways and the optimization of support schemes. Therefore, there is an urgent need to develop a dedicated force monitoring test device for the deformation and stress of roadway surrounding rock to overcome the deficiencies of existing technologies. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings mentioned above by providing a test device for monitoring the deformation and stress changes of the surrounding rock in roadways, thereby enabling effective simulation of relevant roadway conditions and conducting experimental monitoring.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a test device for monitoring the deformation and stress changes of the surrounding rock in a roadway, comprising: The mounting plate has four L-shaped uprights on it; The pressure assembly includes multiple pressing components vertically arranged in a rectangular pattern on the mounting plate. The telescopic ends of each pressing component face downwards, and each telescopic end is provided with a pressure plate. Each pressing component can drive the pressure plate to descend and apply test pressure to the test specimen. The detection component has a mobile trolley at its bottom, which can drive the detection component to move closer to or further away from the test subject. The detection component can be inserted into the corresponding test position of the test subject when moving, and can also rotate, expand or retract to cooperate with the pressing component to perform test measurements on the test subject. A sensing component is mounted on the mounting plate. The sensing component can be activated when the moving trolley moves. When the detection component moves to the target position inside the experimental body, it can sense and collect the real-time position signal of the detection component and match the sensing point of the corresponding pressing component to achieve accurate positioning and matching between the experimental position of the detection component and the corresponding pressing component.

[0006] Furthermore, the experimental body includes an experimental solid, and the experimental solid has perforations inside for simulating changes in the tunnel and surrounding rock. The detection component can be inserted into the perforation and come into contact with the inner wall of the surrounding rock of the experimental solid when it is moved.

[0007] Furthermore, the detection component includes a housing, on which a rotatable and adjustable detection bushing is arranged laterally. The detection bushing is coaxially arranged with the through hole. A first motor is arranged inside the housing, and a transmission component is arranged at the moving end of the first motor. The first motor can cooperate with the transmission component to drive the detection bushing to rotate. An adjusting shaft is slidably inserted inside the detection sleeve. At least two hinge rods are hinged to one end of the adjusting shaft near the experimental body. At least two detection rods are hinged to one end of the detection sleeve near the experimental body. A sensing element is provided at the other end of the detection rod away from the detection sleeve. Each hinge rod is hinged to the corresponding detection rod. When the adjusting shaft slides, it can cooperate with each hinge rod to drive the detection rod to rotate around the connection point with the detection sleeve. An electric cylinder is provided at the end of the detection bushing away from the experimental body, and the moving end of the electric cylinder is connected to the adjustment shaft.

[0008] Furthermore, the detection rod is a telescopic rod, and the sensing element is disposed at the telescopic end of the detection rod.

[0009] Furthermore, it also includes a display terminal, which includes a stress display and a displacement display; The sensing element includes a pressure sensor and a displacement sensor. The pressure sensor is connected to a stress display, and the displacement sensor is connected to a displacement display.

[0010] Furthermore, the mobile vehicle includes a vehicle body, the detection component is fixedly mounted on the vehicle body, at least four wheels are rotatably mounted on the bottom of the vehicle body, and a drive unit is provided on the vehicle body to drive each wheel to rotate synchronously.

[0011] Furthermore, it also includes a track laid on the test ground, with the wheels rotatably mounted on the track, a mounting base provided on the mounting plate, the mounting base being hollow inside, the track extending into the mounting base, and an opening provided on the side of the mounting base near the mobile trolley for it to enter. The sensing component is disposed within the mounting base.

[0012] Furthermore, the sensing component includes a first hydraulic rod and a second hydraulic rod arranged laterally in the mounting base. The moving end of the first hydraulic rod faces the moving trolley, and a push plate is provided at its moving end. The moving trolley can move towards the side closer to the first hydraulic rod and push the push plate to displace it, and press the telescopic end of the first hydraulic rod. A conduit is provided between the first hydraulic rod and the second hydraulic rod to communicate with each other. When the telescopic end of the first hydraulic rod is pressed, the telescopic end of the second hydraulic rod extends. The second hydraulic rod is located on top of each of the pressing components, and the telescopic end of the pressing component faces the opposite direction to the first hydraulic rod. A connecting frame is provided at the telescopic end of the second hydraulic rod, and a trigger plate is provided on the connecting frame. Each of the pressing components is divided into multiple groups along the sliding direction of the trigger plate, and each group of pressing components is provided with a trigger plate, and the trigger plate is provided with a contact point that cooperates with the trigger plate.

[0013] The beneficial effects of this invention are reflected in: In this invention, a hydraulic pressing component with an independent valve, in conjunction with a hydraulic power source system, enables independent control of the operation. The extension and retraction stroke of each pressing component can be controlled as needed. Utilizing a multi-point rectangular pressurization method, differentiated test pressures are applied to different areas of the experimental subject, accurately simulating the actual stress conditions of the surrounding rock in a roadway. Simultaneously, a mobile trolley allows for flexible displacement adjustment of the detection components. Combined with the variable structural characteristics of the detection components—which can rotate, retract, and expand—it adapts to the testing needs of different detection points within the experimental subject. A signal linkage is established between the detection components and the pressing components through a sensing component. When the mobile trolley moves the detection components forward, the sensing component collects their position signals in real time and transmits them synchronously. This provides clear feedback on the specific measurement position and corresponding monitoring information of the experimental subject, allowing staff to intuitively grasp the current test status. It also assists the pressing components in matching corresponding points, achieving precise alignment of detection and pressurization, effectively eliminating manual alignment errors, and improving test accuracy and data reliability. Attached Figure Description

[0014] Figure 1 This is a perspective view of the present invention; Figure 2 This is a cross-sectional view of the structure of the present invention; Figure 3 This is a partial schematic diagram of the present invention; Figure 4 This is a partial cross-sectional view of the detection component in this invention; Figure 5 In this invention Figure 4 A magnified view of a portion of A shown.

[0015] In the picture: 1. Mounting plate; 2. Vertical plate; 3. Pressing component; 4. Pressure plate; 5. Experimental body; 501. Experimental solid; 502. Perforation; 6. Detection assembly; 601. Housing; 602. Detection bushing; 603. First motor; 604. Transmission component; 605. Adjusting shaft; 606. Hinge rod; 607. Detection rod; 608. Sensing element; 609. Electric cylinder; 7. Moving trolley; 701. Car body; 702. Wheel; 703. Drive unit; 8. Track; 9. Mounting base; 10. First hydraulic rod; 11. Push plate; 12. Second hydraulic rod; 13. Connecting frame; 14. Trigger plate; 15. Trigger piece; 16. Contact point. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figure 1-5 This invention discloses an experimental device for monitoring deformation and stress changes of roadway surrounding rock, including a mounting plate 1 with four L-shaped vertical plates 2 on it. An experimental body 5 is placed between the four vertical plates 2. The experimental body 5 is used to simulate a substrate with roadway surrounding rock. A pressure assembly is provided on the mounting plate 1, and the pressure assembly is located on top of the experimental body 5. The pressure assembly includes multiple rectangularly arranged pressing parts 3. The telescopic ends of each pressing part 3 face downwards, and a pressure plate 4 is installed at each telescopic end. Each pressing part 3 can drive the pressure plate 4 to descend and apply test pressure to the experimental body 5.

[0018] The device also includes a hydraulic pump and a hydraulic source, and each pressing component 3 is a hydraulic rod equipped with an independent valve. In use, by opening and closing the corresponding valve, the hydraulic pump and hydraulic source conduct liquid, thereby extending and retracting the telescopic shaft of the corresponding pressing component 3 to the corresponding position, so as to ensure that the pressure plate 4 applies pressure to the corresponding position of the experimental body 5. The hydraulic power system mentioned above is common knowledge in the field, so its specific structural composition and working principle will not be described in detail in this article.

[0019] In one embodiment, the device further includes a detection component 6 and a sensing component. The bottom of the detection component 6 is provided with a moving trolley 7, which can drive the detection component 6 to move towards or away from the experimental body 5. The detection component 6 can be inserted into the corresponding experimental position of the experimental body 5 when moving. It can also rotate, expand or retract to cooperate with the pressing component 3 to perform experimental measurements on the experimental body 5. The sensing component is provided on the mounting plate 1. The sensing component can be activated when the moving trolley 7 moves. When the detection component 6 moves to the target position inside the experimental body 5, it can sense and collect the real-time position signal of the detection component 6 and match it with the sensing point of the corresponding pressing component 3 to achieve accurate positioning and matching between the experimental position of the detection component 6 and the corresponding pressing component 3.

[0020] In practical implementation, the device uses a hydraulic pressing component 3 with an independent valve in conjunction with a hydraulic power source system to achieve independent control operation. The extension and retraction stroke of each pressing component 3 can be controlled as needed. Relying on the multi-point rectangular arrangement of pressurization, differentiated test pressures are applied to different areas of the test body 5 to accurately simulate the real stress conditions of the surrounding rock in the tunnel. At the same time, the mobile trolley 7 enables flexible displacement adjustment of the detection component 6. Combined with the variable structural characteristics of the detection component 6, which can rotate, retract, and expand, it adapts to the testing needs of different detection points inside the test body 5. The sensing component establishes a signal linkage between the detection component 6 and the pressing component 3. When the mobile trolley 7 moves the detection component 6 forward, the sensing component collects its position signal in real time and transmits it synchronously. It can clearly provide feedback on the specific measurement position and corresponding monitoring information of the test body 5, making it convenient for the staff to intuitively grasp the current test status. At the same time, it can assist the pressing component 3 in matching the corresponding points to achieve precise alignment of detection and pressurization, effectively eliminating manual alignment errors and improving test accuracy and data reliability.

[0021] In addition, with the automatic control system, when the detection component 6 moves to the corresponding position, the corresponding pressing component 3 will perform different degrees of pressing tests, thereby improving the flexibility of detection. The above-mentioned automatic control system is common knowledge in the field, so its specific structure and working principle will not be described in detail in this article.

[0022] In one embodiment, the experimental body 5 includes an experimental solid 501, which has a perforation 502 for simulating changes in the tunnel and surrounding rock. When the detection component 6 moves, it can be inserted into the perforation 502 and contact the inner wall of the surrounding rock of the experimental solid 501.

[0023] In practice, the experimental body 5 is made of materials that simulate the tunnel environment. By relying on the perforation 502 in the experimental solid 501, the space and boundary conditions of the real tunnel can be effectively replicated. After the detection component 6 is inserted, it can directly fit with the inner wall of the surrounding rock. The stress and deformation data of the inner wall can be collected without indirect transmission, effectively eliminating transmission errors, improving the authenticity and accuracy of the test data, and more accurately restoring the actual change law of the surrounding rock.

[0024] In one embodiment, the detection component 6 includes a housing 601, on which a rotatable and adjustable detection sleeve 602 is horizontally mounted. The detection sleeve 602 is coaxially arranged with the through hole 502. A first motor 603 is installed inside the housing 601. A transmission component 604 is provided at the moving end of the first motor 603. The first motor 603 can cooperate with the transmission component 604 to drive the detection sleeve 602 to rotate. The transmission component 604 may be two sprockets and a chain connected thereto. The two sprockets are coaxially mounted on the shafts of the detection sleeve 602 and the first motor 603, respectively.

[0025] An adjusting shaft 605 is slidably inserted into the detection sleeve 602. At least two hinge rods 606 are hinged to one end of the adjusting shaft 605 near the experimental body 5. At least two detection rods 607 are hinged to one end of the detection sleeve 602 near the experimental body 5. A sensing element 608 is provided at the other end of the detection rod 607 away from the detection sleeve 602. Each hinge rod 606 is hinged to the corresponding detection rod 607. When the adjusting shaft 605 slides, it can cooperate with each hinge rod 606 to drive the detection rod 607 to rotate around the connection point with the detection sleeve 602. An electric cylinder 609 is provided at the end of the detection sleeve 602 away from the experimental body 5. The moving end of the electric cylinder 609 is connected to the adjusting shaft 605.

[0026] In practice, the first motor 603 is started, which, together with the transmission component 604, drives the detection sleeve 602 to rotate. The electric cylinder 609 is started, which drives the adjustment shaft 605 to move linearly. During the movement, it can work with each hinge rod 606 to drive the corresponding detection rod 607 to move in an umbrella shape, so as to perform the unfolding or retracting action. With the rotation adjustment, a comprehensive and flexible detection can be performed on the corresponding perforation 502 of the experimental solid 501.

[0027] In one embodiment, the detection rod 607 is a telescopic rod, and the sensing element 608 is disposed at the telescopic end of the detection rod 607.

[0028] In practice, the detection rod 607 can be an electric push rod, which can actively drive the sensing element 608 to move. This method can detect perforations 502 of different shapes, thereby improving the flexibility of detection.

[0029] In one embodiment, a display terminal is also included, which includes a stress display and a displacement display; The sensing element 608 includes a pressure sensor and a displacement sensor. The pressure sensor is connected to a stress display, and the displacement sensor is connected to a displacement display.

[0030] In practice, the display terminal of the device can classify and visualize the detection data. The surrounding rock stress and displacement data collected by the sensing element 608 can be independently transmitted to the stress display and displacement display respectively, so as to realize the synchronous and independent display of the two types of detection parameters.

[0031] In one embodiment, the mobile trolley 7 includes a trolley body 701, a detection component 6 is fixedly mounted on the trolley body 701, at least four wheels 702 are rotatably mounted on the bottom of the trolley body 701, and a drive unit 703 is provided on the trolley body 701 to drive each wheel 702 to rotate synchronously.

[0032] In practice, the drive unit 703 is used to drive each wheel 702 to rotate synchronously, so that the vehicle body 701 can move the detection component 6 to the side closer to or farther away from the experimental body 5.

[0033] In one embodiment, the system also includes a track 8 laid on the test ground, wheels 702 rotatably mounted on the track 8, a mounting base 9 mounted on the mounting plate 1, the mounting base 9 being hollow inside, the track 8 extending into the mounting base 9, and an opening for the mobile trolley 7 to enter the mounting base 9 on the side of the mounting base 9, and a sensing component disposed inside the mounting base 9.

[0034] In one embodiment, the sensing component includes a first hydraulic rod 10 and a second hydraulic rod 12 horizontally mounted in the mounting base 9. The second hydraulic rod 12 and the first hydraulic rod 10 are distributed vertically. The moving end of the first hydraulic rod 10 faces the moving trolley 7, and a push plate 11 is provided at its moving end. The moving trolley 7 can move towards the side closer to the first hydraulic rod 10 and push the push plate 11 to displace it, thereby pressing the telescopic end of the first hydraulic rod 10. A conduit is provided between the first hydraulic rod 10 and the second hydraulic rod 12 for mutual communication. When the telescopic end of the first hydraulic rod 10 is pressed, the telescopic end of the second hydraulic rod 12 extends. The second hydraulic rod 12 is located on top of each pressing component 3, and the telescopic end of the pressing component 3 faces the opposite direction to the first hydraulic rod 10.

[0035] A connecting frame 13 is installed at the telescopic end of the second hydraulic rod 12. A trigger plate 14 is provided on the connecting frame 13. Each pressing component 3 is divided into multiple groups along the sliding direction of the trigger plate 14, and each group of pressing components 3 is provided with a trigger plate 15. The trigger plate 15 is provided with a contact point 16 that cooperates with the trigger plate 14.

[0036] In specific implementation, the hydraulic transmission between the first hydraulic rod 10 and the second hydraulic rod 12 is achieved through a connecting conduit. When the moving trolley 7 moves and squeezes the push plate 11, causing the first hydraulic rod 10 to contract under pressure, the second hydraulic rod 12 is driven to extend and retract through hydraulic transmission, thereby driving the connecting frame 13 and the trigger plate 14 to move synchronously. By utilizing the contact between the trigger plate 14 and the trigger pieces 15 and contacts 16 of each group of pressing components 3, the corresponding pressurization components are precisely activated according to the detection position, realizing the mechanical linkage matching between the detection point and the pressurization area. This purely mechanical hydraulic trigger linkage structure does not require the participation of electrical control signals, avoiding problems such as delay and interference failure of electrical control signals. It has strong structural stability and good environmental adaptability, effectively improving the accuracy of detection and pressurization alignment and the reliability of test operation.

[0037] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0038] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0039] Additionally, "multiple" refers to two or more.

[0040] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A test device for monitoring deformation and stress changes in the surrounding rock of a roadway, characterized in that, include: Mounting plate (1), on which four L-shaped upright plates (2) are provided; The pressure assembly includes multiple pressing components (3) arranged vertically on the mounting plate (1) in a rectangular arrangement. The telescopic ends of each pressing component (3) face downwards, and each telescopic end is provided with a pressure plate (4). Each pressing component (3) can drive the pressure plate (4) to descend and apply test pressure to the test body (5). The detection component (6) has a mobile trolley (7) at its bottom. The mobile trolley (7) can drive the detection component (6) to move closer to or further away from the test body (5). The detection component (6) can be inserted into the corresponding test position of the test body (5) when moving. It can also rotate, unfold or retract to cooperate with the pressing component (3) to perform test measurements on the test body (5). The sensing component is mounted on the mounting plate (1). The sensing component can be activated when the moving trolley (7) moves. When the detection component (6) moves to the target position inside the experimental body (5), it can sense and collect the real-time position signal of the detection component (6) and match the sensing point of the corresponding pressing component (3) to achieve accurate positioning matching between the experimental position of the detection component (6) and the corresponding pressing component (3).

2. The test device for monitoring deformation and stress changes of surrounding rock in roadways according to claim 1, characterized in that: The experimental body (5) includes an experimental solid (501), and the experimental solid (501) has perforations (502) inside for simulating changes in the tunnel and surrounding rock. The detection component (6) can be inserted into the perforation (502) and contact the inner wall of the surrounding rock of the experimental solid (501) when it is moved.

3. The test device for monitoring deformation and stress changes of surrounding rock in roadways according to claim 2, characterized in that: The detection component (6) includes a housing (601), on which a rotatable and adjustable detection bushing (602) is arranged laterally. The detection bushing (602) is coaxially arranged with the through hole (502). A first motor (603) is arranged inside the housing (601). A transmission component (604) is arranged at the moving end of the first motor (603). The first motor (603) can cooperate with the transmission component (604) to drive the detection bushing (602) to rotate. An adjusting shaft (605) is slidably inserted inside the detection sleeve (602). At least two hinge rods (606) are hinged to one end of the adjusting shaft (605) near the experimental body (5). At least two detection rods (607) are hinged to one end of the detection sleeve (602) near the experimental body (5). A sensing element (608) is provided at the other end of the detection rod (607) away from the detection sleeve (602). Each hinge rod (606) is hinged to the corresponding detection rod (607). When the adjusting shaft (605) slides, it can cooperate with each hinge rod (606) to drive the detection rod (607) to rotate around the connection point with the detection sleeve (602). An electric cylinder (609) is provided at the end of the detection bushing (602) away from the experimental body (5), and the moving end of the electric cylinder (609) is connected to the adjusting shaft (605).

4. The test device for monitoring deformation and stress changes of surrounding rock in roadways according to claim 3, characterized in that: The detection rod (607) is a telescopic rod, and the sensing element (608) is disposed at the telescopic end of the detection rod (607).

5. The test device for monitoring deformation and stress changes of surrounding rock in roadways according to claim 3, characterized in that: It also includes a display terminal, which includes a stress display and a displacement display; The sensing element (608) includes a pressure sensor and a displacement sensor, wherein the pressure sensor is connected to a stress display and the displacement sensor is connected to a displacement display.

6. The test device for monitoring deformation and stress changes of surrounding rock in roadways according to claim 1, characterized in that: The mobile trolley (7) includes a body (701), the detection component (6) is fixedly mounted on the body (701), the bottom of the body (701) is rotatably provided with at least four wheels (702), and a drive unit (703) is provided on the body (701) for driving each wheel (702) to rotate synchronously.

7. The test device for monitoring deformation and stress changes of surrounding rock in a roadway according to claim 6, characterized in that: It also includes a track (8) laid on the test ground, the wheels (702) being rotatably mounted on the track (8), a mounting seat (9) being provided on the mounting plate (1), the mounting seat (9) being hollow inside, the track (8) extending into the mounting seat (9), and the mounting seat (9) having an opening on the side near the moving trolley (7) for it to enter. The sensing component is disposed within the mounting base (9).

8. The test device for monitoring deformation and stress changes of surrounding rock in roadways according to claim 7, characterized in that: The sensing component includes a first hydraulic rod (10) and a second hydraulic rod (12) arranged laterally in the mounting base (9). The moving end of the first hydraulic rod (10) faces the moving trolley (7), and a push plate (11) is provided at its moving end. The moving trolley (7) can move to the side closer to the first hydraulic rod (10) and push the push plate (11) to displace it, and press the telescopic end of the first hydraulic rod (10). A conduit is provided between the first hydraulic rod (10) and the second hydraulic rod (12) for mutual communication. When the telescopic end of the first hydraulic rod (10) is pressed, the telescopic end of the second hydraulic rod (12) extends out. The second hydraulic rod (12) is located on the top of each of the pressing components (3), and the telescopic end of the pressing component (3) faces the opposite direction to the first hydraulic rod (10). A connecting frame (13) is provided at the telescopic end of the second hydraulic rod (12). A trigger plate (14) is provided on the connecting frame (13). Each pressing component (3) is divided into multiple groups along the sliding direction of the trigger plate (14). Each pressing component (3) in each group is provided with a trigger plate (15). The trigger plate (15) is provided with a contact point (16) that cooperates with the trigger plate (14).

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